Night vision apparatus is commonly used by aviators to enhance their visibility while flying during night or other low light conditions. Conventional night vision apparatus comprises a night vision goggle including image intensifier tubes, lens assemblies and a complex mounting assembly that provides for numerous adjustments of the goggle position with respect to the user. All of these items combine to provide a relatively heavy device. Such apparatus also includes a relatively light weight power pack that houses a battery or batteries and a circuit board. The power pack is mechanically and electrically coupled to the goggle for operating the goggle and the power pack is, in turn, fixed to the aviators' helmet. As a consequence, the entire weight of the night vision apparatus is supported by the aviator's neck.
When a pilot ejects from an aircraft, the cockpit canopy is ejected from the aircraft and then the aviator is ejected. The acceleration of the aircraft, wind entering the cockpit, the inclination of the aircraft and the large acceleration forces developed as the pilot is suddenly ejected from the aircraft, acting alone or in combination, provide a significant risk that the pilot will be injured.
Because of the heavy weight of the night vision apparatus and because it is supported by the aviator's neck, there is a considerable risk that the apparatus will cause severe neck injuries to the aviator during the ejection.
To reduce this risk of neck injury there are known arrangements that release the night vision goggles from the aviator's helmet as the aviator is subjected to severe acceleration forces during the ejection process. In the known arrangements, however, the relatively light weight power pack does not release. Thus, with the power pack fixed to the helmet, it, the power pack, has the potential to become entangled with the parachute risers during ejection. If the power pack becomes so entangled, it can interfere with the proper opening of the parachute providing additional risk to the aviator.
Accordingly, it is desirable to have a mounting arrangement for night vision apparatus wherein both the goggle and the power pack are automatically released from the aviator's helmet as soon as possible during the ejection process.